Issue #2073811 by dawehner, pwolanin, joelpittet, Cottser, Mark Carver, steveoliver: Add a url generator twig extension.

Issue #1987406 by jenlampton, Petr Illek, forbesgraham, herom, jerdavis, Jon Pugh, sanguis, idflood, ezeedub, shanethehat, joelpittet | Cottser: Node.module - Convert theme_ functions to Twig.